<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        //Array.from
        let  str="abcdref";
        console.log(Array.from(str));//['a', 'b', 'c', 'd', 'r', 'e', 'f']
        console.log(Array.from(str).sort());//排序
    </script>
</body>
</html>